What about the battle of Armageddon? Again this seems to be a Christian/Revelation idea. Is there any foreshadowing of a great final battle in ancient Jewish scriptures?

Perhaps surprising to some, like Satan, the notion of a final day of Judgement or Vengance is also mentioned throughout Jewish scripture.

3 Then shall the Lord go forth, and fight against those nations, as when he fought in the day of battle.
4 And his feet shall stand in that day upon the mount of Olives, which is before Jerusalem on the east, and the mount of Olives shall cleave in the midst thereof toward the east and toward the west, and there shall be a very great valley; and half of the mountain shall remove toward the north, and half of it toward the south.

Zechariah 14:3-4 (KJV)

9 Proclaim ye this among the Gentiles; Prepare war, wake up the mighty men, let all the men of war draw near; let them come up:
10 Beat your plowshares into swords, and your pruninghooks into spears: let the weak say, I am strong.
11 Assemble yourselves, and come, all ye heathen, and gather yourselves together round about: thither cause thy mighty ones to come down, O Lord.
12 Let the heathen be wakened, and come up to the valley of Jehoshaphat: for there will I sit to judge all the heathen round about.

Joel 3:9-12 (KJV)

1 Who is this that cometh from Edom, with dyed garments from Bozrah? this that is glorious in his apparel, travelling in the greatness of his strength? I that speak in righteousness, mighty to save.
2 Wherefore art thou red in thine apparel, and thy garments like him that treadeth in the winefat?
3 I have trodden the winepress alone; and of the people there was none with me: for I will tread them in mine anger, and trample them in my fury; and their blood shall be sprinkled upon my garments, and I will stain all my raiment.
4 For the day of vengeance is in mine heart, and the year of my redeemed is come.
5 And I looked, and there was none to help; and I wondered that there was none to uphold: therefore mine own arm brought salvation unto me; and my fury, it upheld me.
6 And I will tread down the people in mine anger, and make them drunk in my fury, and I will bring down their strength to the earth.

Isaiah 63:1-6 (KJV)

Compare the above to these New Testament scriptures:

7 And to you who are troubled rest with us, when the Lord Jesus shall be revealed from heaven with his mighty angels,
8 In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ:
9 Who shall be punished with everlasting destruction from the presence of the Lord, and from the glory of his power;
10 When he shall come to be glorified in his saints, and to be admired in all them that believe (because our testimony among you was believed) in that day.

2 Thess 1:7-10 (KJV)

3 Knowing this first, that there shall come in the last days scoffers, walking after their own lusts,
4 And saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation.
5 For this they willingly are ignorant of, that by the word of God the heavens were of old, and the earth standing out of the water and in the water:
6 Whereby the world that then was, being overflowed with water, perished:
7 But the heavens and the earth, which are now, by the same word are kept in store, reserved unto fire against the day of judgment and perdition of ungodly men.
10 But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up.

2 Peter 3:3-7, 10 (KJV)

16 And he gathered them together into a place called in the Hebrew tongue Armageddon.
17 And the seventh angel poured out his vial into the air; and there came a great voice out of the  temple of heaven, from the throne, saying, It is done.
18 And there were voices, and thunders, and lightnings; and there was a great earthquake, such as was  not since men were upon the earth, so mighty an earthquake, and so great.
19 And the great city was divided into three parts, and the cities of the nations fell: and great Babylon  came in remembrance before God, to give unto her the cup of the wine of the fierceness of his wrath.

Revelation 16:16-19 (KJV)

11 And I saw heaven opened, and behold a white horse; and he that sat upon him was called Faithful and True, and in righteousness he doth judge and make war.
12 His eyes were as a flame of fire, and on his head were many crowns; and he had a name written, that no man knew, but he himself.
13 And he was clothed with a vesture dipped in blood: and his name is called The Word of God.
14 And the armies which were in heaven followed him upon white horses, clothed in fine linen, white and clean.
15 And out of his mouth goeth a sharp sword, that with it he should smite the nations: and he shall rule them with a rod of iron: and he treadeth the winepress of the fierceness and wrath of Almighty God. 16 And he hath on his vesture and on his thigh a name written, KING OF KINGS, AND Lord OF Lords.
17 And I saw an angel standing in the sun; and he cried with a loud voice, saying to all the fowls that fly in the midst of heaven, Come and gather yourselves together unto the supper of the great God; 18 That ye may eat the flesh of kings, and the flesh of captains, and the flesh of mighty men, and the flesh of horses, and of them that sit on them, and the flesh of all men, both free and bond, both small and great.
19 And I saw the beast, and the kings of the earth, and their armies, gathered together to make war against him that sat on the horse, and against his army.
20 And the beast was taken, and with him the false prophet that wrought miracles before him, with which he deceived them that had received the mark of the beast, and them that worshipped his image. These both were cast alive into a lake of fire burning with brimstone.
21 And the remnant were slain with the sword of him that sat upon the horse, which sword proceeded out of his mouth: and all the fowls were filled with their flesh.

Revelation 19:11-21 (KJV)